Casper’s Odd Fellows Building, constructed in 1952, reflects the modern-style architecture that was popular during the postwar era and serves as a reminder of the community development, planning and the social history of the time. This structure is named on the National Register of Historic Places.

Though the site was an important river crossing on the early frontier, the town of Casper did not begin until 1888, when the Fremont, Elkhorn & Missouri Valley Railroad reached the area. The town immediately became an important shipping point for cattle and wool. The first oil refinery was built in 1895 to process crude oil from the Salt Creek Oil Field, 40 miles to the north. The first true oil boom began after 1910 and lasted through the mid 1920s, and the town’s fortunes have been closely connected to the energy business ever since. In 2010 the city’s population passed 55,000. Casper continues as a retail, medical and energy-industry service hub.

In 1830, a party of fur traders led by William Sublette took wagons to the trade’s annual rendezvous at the headwaters of Wind River that year, east of the Continental Divide. Two years later, Capt. Benjamin Bonneville took the first caravan of wagons across the Divide at South Pass.

Evanston lawyer Clarence Clark became Wyoming’s first congressional representative in 1890. In 1895, the legislature elected him to the U.S. Senate. Sen. F. E. Warren, Rep. Frank Mondell and Clark made an all-Republican congressional triumvirate for more than two decades until Clark lost to John B. Kendrick in 1916.

Bill Carlisle robbed passengers on the Union Pacific Railroad three times in 1916 and once more in 1919, after escaping from the state penitentiary in a box of shirts. In 1936 he was paroled and opened a café and tourist court in Laramie, and later wrote a book about his remarkable life.

White settlement in Sublette County, Wyo. traces its roots to the late 1870s, when cattlemen brought herds to the pastures where North, Middle and Piney Creeks join the Green River. The town of Big Piney was incorporated there in 1913. The next year, neighboring Marbleton was incorporated a mile away, on higher ground on the bench above Piney Creek. Every effort to combine the two towns has failed, and they continue to maintain separate governments though they share most other services. The energy industry is now the major employer in both communities. Big Piney registered a population of 552 in the 2010 census, and Marbleton, 1,094.

The scenic Bighorn Basin and world-class fishing opportunities on the Bighorn River have made Big Horn County, Wyo., a tourist destination, but the area is also rich in oil and natural gas—and history. People have lived in the area since ancient times, as evidenced by the Medicine Wheel near the county’s northern corer. Ranch families still raise cattle and sheep, and farm families still raise sugar beets as they have for more than a century.

From 1942 through most of 1945, about 10,000 Japanese-Americans from the West Coast of United States lived behind barbed wire in tarpaper barracks at the Heart Mountain Relocation Center between Cody and Powell, Wyo. in Park County—one of ten such camps around the nation during World War II. The center was briefly Wyoming’s third-largest town. When hundreds of young men in the camp were drafted into the U.S. military, 63 resisted, feeling they had been denied their constitutional rights. They and seven more leaders of the group were sentenced to federal prison. In the 1980s, Congress passed a law granting an apology and $20,000 to every survivor of the camps.

Billy Owen never saw a railroad until he was eight years old. His mother had told him about railroads. But in his mind as he traveled east by wagon train across Wyoming in the spring of 1868, he had imagined railroad wheels that looked something like wagon wheels. They rolled in grooves. Each groove was made by two rails. That meant it took four rails, as he imagined it, to make a track.

The Casper Army Air Base was built quickly in 1942 to train bomber crews for World War II combat. The facility trained more than 16,000 men before the end of the war. Its population grew to a third of the size of Casper’s, bringing prosperity and a lively social life to the town. The base closed in 1945, when the war ended.